Breeding ecology and distribution of culex mosquitoes in Minna, Nigeria: Implications for vector control

The ecological characteristics of mosquito breeding sites are a fundamental determinant of population dynamics and, consequently, the transmission potential of mosquito-borne diseases. To elucidate the local factors driving vector proliferation, this study investigated the occurrence and spatial distribution of Culex mosquito larvae across six distinct and representative breeding habitats within Minna, Niger State, Nigeria. Over the course of the survey, larval sampling was conducted in rice fields, open drainage gutters, dams, slow-moving streams, temporary rain pools, and water-collecting discarded tyres. Collected larvae were transported to an insectary and reared under standardized conditions to adulthood to facilitate accurate species identification. The relative abundance of Culex mosquitoes was then calculated for each habitat type to determine their comparative contribution to the local vector population. The results revealed a clear and striking hierarchy in larval density. Rice fields were the most productive habitat, accounting for a substantial 36.0% of all larvae collected. This was followed by gutters (21.6%), which served as significant urban breeding grounds. Dams (12.6%), streams (11.6%), and rain pools (10.7%) supported moderate densities, while discarded tyres (7.5%) represented the least common habitat. The marked predominance of rice fields and gutters underscores their exceptional ecological suitability for Culex proliferation, a phenomenon likely driven by persistent stagnant water, high organic nutrient loads from decomposition and waste, and minimal environmental disturbance. These findings strongly indicate that human activities and specific habitat types are primary drivers shaping the distribution and abundance of mosquito populations in the region. A deep understanding of this localized breeding ecology is therefore critical for designing and deploying effective, targeted vector control strategies. Interventions focusing on environmental management and larval source reduction in the identified priority habitats specifically rice fields and drainage systems could substantially suppress Culex mosquito populations and thereby reduce the associated risks of arboviral and filarial disease transmission in Minna and similar endemic settings.